Why should I keep enduring, if I can't lose my salvation?

I give eternal life to them. They will never perish, and no one will snatch them out of my hand. My Father, who has given them to me, is greater than all. No one is able to snatch them out of my Father’s hand.And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand. My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father’s hand.

being confident of this very thing, that he who began a good work in you will complete it until the day of Jesus Christ.Being confident of this very thing, that he which hath begun a good work in you will perform it until the day of Jesus Christ:

Whom he predestined, those he also called. Whom he called, those he also justified. Whom he justified, those he also glorified.Moreover whom he did predestinate, them he also called: and whom he called, them he also justified: and whom he justified, them he also glorified.

Beware, brothers, lest perhaps there be in any one of you an evil heart of unbelief, in falling away from the living God; but exhort one another day by day, so long as it is called “today”; lest any one of you be hardened by the deceitfulness of sin. For we have become partakers of Christ, if we hold fast the beginning of our confidence firm to the end:Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God. But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. For we are made partakers of Christ, if we hold the beginning of our confidence stedfast unto the end;

Therefore let him who thinks he stands be careful that he doesn’t fall.Wherefore let him that thinketh he standeth take heed lest he fall.

But he who endures to the end, the same will be saved.But he that shall endure unto the end, the same shall be saved.

I am coming quickly! Hold firmly that which you have, so that no one takes your crown.Behold, I come quickly: hold that fast which thou hast, that no man take thy crown.

They went out from us, but they didn’t belong to us; for if they had belonged to us, they would have continued with us. But they left, that they might be revealed that none of them belong to us.They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us: but they went out, that they might be made manifest that they were not all of us.

That in the good ground, these are such as in an honest and good heart, having heard the word, hold it tightly, and produces fruit with patience.But that on the good ground are they, which in an honest and good heart, having heard the word, keep it, and bring forth fruit with patience.

But we are not of those who shrink back to destruction, but of those who have faith to the saving of the soul.But we are not of them who draw back unto perdition; but of them that believe to the saving of the soul.

So then, my beloved, even as you have always obeyed, not only in my presence, but now much more in my absence, work out your own salvation with fear and trembling. For it is God who works in you both to will and to work, for his good pleasure.Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling. For it is God which worketh in you both to will and to do of his good pleasure.

Brothers, I don’t regard myself as yet having taken hold, but one thing I do. Forgetting the things which are behind, and stretching forward to the things which are before, I press on toward the goal for the prize of the high calling of God in Christ Jesus.Brethren, I count not myself to have apprehended: but this one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, I press toward the mark for the prize of the high calling of God in Christ Jesus.

I have fought the good fight. I have finished the course. I have kept the faith.I have fought a good fight, I have finished my course, I have kept the faith:

Therefore let us also, seeing we are surrounded by so great a cloud of witnesses, lay aside every weight and the sin which so easily entangles us, and let us run with patience the race that is set before us, looking to Jesus, the author and perfecter of faith, who for the joy that was set before him endured the cross, despising its shame, and has sat down at the right hand of the throne of God.Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us, Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God.

Don’t be afraid of the things which you are about to suffer. Behold, the devil is about to throw some of you into prison, that you may be tested; and you will have oppression for ten days. Be faithful to death, and I will give you the crown of life.Fear none of those things which thou shalt suffer: behold, the devil shall cast some of you into prison, that ye may be tried; and ye shall have tribulation ten days: be thou faithful unto death, and I will give thee a crown of life.

He who calls you is faithful, who will also do it.Faithful is he that calleth you, who also will do it.